Comment # 4 on bug 109135 from Michel Dänzer

Looks VCE related:

Dec 24 21:12:11.223675 tom-comp kernel: [drm:amdgpu_vce_ring_test_ring
[amdgpu]] *ERROR* amdgpu: ring 12 test failed
Dec 24 21:12:11.223708 tom-comp kernel: [drm:amdgpu_device_init.cold.17
[amdgpu]] *ERROR* hw_init of IP block <vce_v2_0> failed -110

If you can live without hardware accelerated video encoding,
amdgpu.ip_block_mask=0xff on the kernel command line might serve as a
workaround.